Packaging Material Ruzivo - Chii Chinokonzeresa Shanduko Yeruvara rwePlastiki Zvigadzirwa?

• Iyo oxidative degradation yezvinhu zvakasvibirira inogona kukonzera kushanduka kana ichiumbwa pakupisa kwakanyanya;
• Discoloration yeruvara pakupisa kwakanyanya kunokonzeresa kushanduka kwezvigadzirwa zvepurasitiki;
• Iyo kemikari inoita pakati peruvara uye mbishi zvinhu kana zvinowedzera zvinokonzeresa kushanduka;
• Kuita pakati pezvinowedzerwa uye otomatiki oxidation yezvinowedzera zvinokonzeresa shanduko yemavara;
• Tautomerization yemavara pigment pasi pechiito chechiedza uye kupisa kuchakonzera shanduko yemavara ezvigadzirwa;
• Mhepo inosvibisa inogona kukonzera shanduko muzvigadzirwa zvepurasitiki.

1. Inokonzerwa nePlastiki Molding

1) Iyo oxidative degradation yezvinhu zvakasvibirira inogona kukonzera discoloration kana ichiumbwa pakupisa kwakanyanya

Kana mhete yekudziya kana kupisa ndiro yepurasitiki yekuumba michina yekugadzira inogara iri munzvimbo yekudziya nekuda kwekunze kwekutonga, zviri nyore kuita kuti kupisa kwenzvimbo kuve kwakanyanya, izvo zvinoita kuti iyo mbishi oxidize uye iparare pakupisa kwakanyanya. Kune avo kupisa-sensitive mapurasitiki, akadai sePVC, zviri nyore kuti Kana chiitiko ichi chikaitika, kana chakakomba, chinopisa uye chichiita yero, kana kunyange dema, chichiperekedzwa nehuwandu hwepasi molecular volatiles inofashukira.

Kudzikira uku kunosanganisira maitiro akadaidepolymerization, random chain scission, kubviswa kwemapoka emativi uye yakaderera molecular uremu zvinhu.

• Depolymerization

Iyo cleavage reaction inoitika pane terminal chain link, zvichiita kuti cheni chinongedzo chidonha chimwe nechimwe, uye iyo inogadzirwa monomer inokurumidza kunyungudika. Panguva ino, huremu hwemamorekuru hunochinja zvishoma nezvishoma, senge reverse process yecheni polymerization. Zvakadai se thermal depolymerization yemethyl methacrylate.

• Random Chain Scission (Kudzikisirwa)

Zvinozivikanwawo sekuti zvakangoerekana zvaputsika kana macheni asina kurongeka. Pasi pekuita kwe mechanical force, high-energy radiation, ultrasonic waves kana chemical reagents, iyo polymer cheni inotyoka pasina poindi yakatarwa kuti ibudise yakaderera-molecular-weight polymer. Ndiyo imwe yenzira dzekuparara kwepolymer. Kana cheni yepolymer ichidzikira zvisina tsarukano, huremu hwemamorekuru hunodonha nekukurumidza, uye kuderera kwehuremu hwepolymer kudiki kwazvo. Semuenzaniso, degradation mechanism ye polyethylene, polyene uye polystyrene inonyanya kuparara.

Kana mapolymers akadai sePE akaumbwa pakupisa kwakanyanya, chero chinzvimbo checheni huru chinogona kutyorwa, uye huremu hwemamorekuru hunodonha nekukurumidza, asi goho remonomeri idiki kwazvo. Iyi mhando yemaitiro inonzi random chain scission, dzimwe nguva inonzi degradation, polyethylene Iwo emahara radicals akaumbwa mushure mecheni scission anoshanda zvakanyanya, akakomberedzwa neakawanda echipiri hydrogen, anowanzo kuchinjisa cheni, uye anenge asina monomers anogadzirwa.

• Kubviswa kwezvinhu zvinotsiva

PVC, PVAc, zvichingodaro inogona kuita substituent yekubvisa reaction kana yapiswa, saka bani rinowanzo oneka pa thermogravimetric curve. Apo polyvinyl chloride, polyvinyl acetate, polyacrylonitrile, polyvinyl fluoride, nezvimwewo zvinopisa, zvinotsiva zvichabviswa. Kutora polyvinyl chloride (PVC) semuenzaniso, PVC inogadziriswa patembiricha iri pasi pe180 ~ 200 ° C, asi pakadzika yakadzika (senge 100 ~ 120 ° C), inotanga kudhirojeni (HCl), uye inorasikirwa neHCl zvakanyanya. nekukurumidza kusvika ku200 ° C. Naizvozvo, panguva yekugadzira (180-200 ° C), iyo polymer inoita kunge yakasviba muruvara uye kuderera musimba.

Yemahara HCl ine catalytic mhedzisiro pa dehydrochlorination, uye metal chlorides, senge ferric chloride inoumbwa nekuita kwehydrogen chloride uye michina yekugadzira, inosimudzira catalysis.

Zvishoma kubva muzana zveasidhi zvinotora, zvakadai sebarium stearate, organotin, lead compounds, nezvimwewo, zvinofanira kuwedzerwa kuPVC panguva yekupisa kupisa kuti ivandudze kugadzikana kwayo.

Kana tambo yekutaurirana ichishandiswa kupendesa tambo yekutaurirana, kana polyolefin layer pawaya yemhangura isina kugadzikana, green copper carboxylate ichaumbwa pane iyo polymer-copper interface. Aya maitiro anosimudzira kupararira kwemhangura mupolymer, ichimhanyisa iyo catalytic oxidation yemhangura.

Naizvozvo, kuitira kuderedza oxidative degradation rate ye polyolefins, phenolic kana aromatic amine antioxidants (AH) inowanzowedzerwa kumisa maitiro ari pamusoro uye kugadzira isingashande emahara radicals A·: ROO·+AH-→ROOH+A·

• Oxidative Degradation

Zvigadzirwa zvepolymer zvakafumurwa kumhepo zvinotora okisijeni uye zvinopinda oxidation kuti igadzire mahydroperoxides, inowora kuti ibudise nzvimbo dzinoshanda, inogadzira mahara radicals, uye yobva yaita mahara radical chain reactions (kureva, auto-oxidation process). Mapolymers anooneswa okisijeni mumhepo panguva yekugadziriswa nekushandiswa, uye kana yapiswa, kuderedzwa kweoxidative kunokwidziridzwa.

Iyo yekupisa oxidation ye polyolefins ndeyemahara radical chain reaction mechanism, ine autocatalytic maitiro uye inogona kukamurwa kuita matanho matatu: kutangisa, kukura uye kupera.

Iyo ketani scission inokonzerwa neiyo hydroperoxide boka inotungamira kuderera kwehuremu hwemamorekuru, uye zvigadzirwa zvikuru zvechisikisi madoro, aldehydes, uye ketoni, izvo zvinozopedzisira zvave oxidized kune carboxylic acid. Carboxylic acids inobata basa guru mu catalytic oxidation yesimbi. Oxidative degradation ndicho chikonzero chikuru chekudzikira kwechimiro chemuviri uye chemichina yezvigadzirwa zvepolymer. Oxidative degradation inosiyana neiyo molecular chimiro chepolymer. Kuvapo kweokisijeni kunogonawo kuwedzera kukuvadzwa kwechiedza, kupisa, mwaranzi uye simba remagetsi pamapolymers, zvichikonzera kukanganisa kwakanyanya. MaAntioxidants anowedzerwa kuma polymers kuti anonoke kuderera kweoxidative.

2) Kana plastiki ikagadziriswa uye kuumbwa, iyo colorant inoora, inopera uye inochinja ruvara nekuda kwekutadza kwayo kutsungirira kupisa kwakanyanya.

Idzo pigment kana madhayi anoshandiswa kuisa mavara epurasitiki ane tembiricha inogumira. Kana tembiricha iyi yasvika, pigment kana madhayi anozochinja kemikari kuti abudise akasiyana ezasi mamorekuru uremu makomisheni, uye maitiro avo maitiro akaoma kunzwisisa; mavara akasiyana ane maitiro akasiyana. Uye zvigadzirwa, kupisa kwekushisa kweakasiyana pigment kunogona kuedzwa nenzira dzekuongorora dzakadai sekuderedza uremu.

2. Colorants React with Raw Materials

Kuita pakati pemavara uye mbichana kunonyanya kuratidzwa mukugadziriswa kwemamwe pigment kana madhayi uye mbishi. Aya maitiro emakemikari anozotungamira kune shanduko muhue uye kushatiswa kwemapolymers, nekudaro kuchinja maitiro ezvigadzirwa zvepurasitiki.

• Kuderedza Reaction

Mamwe mapolymer akakwira, akadai senaironi uye aminoplasts, ane asidhi akasimba ekudzikisa maajenti munzvimbo yakanyungudutswa, ayo anogona kuderedza nekudzima pigment kana dhayi dzakagadzikana pakupisa tembiricha.

• Alkaline Exchange

Alkaline pasi masimbi muPVC emulsion mapolymers kana mamwe mapolypropylenes akatsiga anogona "kutsinhana kwepasi" ane alkaline pasi simbi mune colorants kushandura ruvara kubva kubhuruu-kutsvuka kuenda kuorenji.

PVC emulsion polymer inzira iyo VC inopolymerized nekukandira mune emulsifier (senge sodium dodecylsulfonate C12H25SO3Na) ine aqueous solution. Mhinduro yacho ine Na+; kuitira kuvandudza kupisa uye oksijeni kuramba kwePP, 1010, DLTDP, nezvimwewo zvinowanzowedzerwa. Oxygen, antioxidant 1010 is a transesterification reaction catalyzed by 3,5-di-tert-butyl-4-hydroxypropionate methyl ester uye sodium pentaerythritol, uye DLTDP inogadzirirwa nekuita Na2S aqueous solution ine acrylonitrile Propionitrile iri hydrolyodized uye pakupedzisira hydrothiodized kubudisa asidi. yakawanikwa ne esterification ine lauryl doro. Mhinduro yacho inewo Na+.

Munguva yekuumbwa nekugadziriswa kwezvigadzirwa zvepurasitiki, iyo yakasara Na+ mune yakasvibirira ichaita nedhamu pigment ine maion esimbi seCIPigment Red48:2 (BBC kana 2BP): XCa2++2Na+→XNa2+ +Ca2+

• Kuita pakati pePigment neHydrogen Halides (HX)

Kana kutonhora kuchikwira kusvika ku170 ° C kana pasi pekuita kwechiedza, PVC inobvisa HCI kuti iite conjugated double bond.

Halogen-ine flame-retardant polyolefin kana ane mavara-etardant epurasitiki zvigadzirwa zvakare dehydrohalogenated HX kana yakaumbwa pakupisa kwakanyanya.

1) Ultramarine uye HX maitiro

Ultramarine yebhuruu pigment inoshandiswa zvakanyanya mupurasitiki coloring kana kubvisa yero mwenje, isanganiswa yesarufa.

2) Mhangura yegoridhe poda pigment inomhanyisa iyo oxidative kuora kwePVC mbishi zvinhu.

Mhangura pigment inogona kuve oxidized kuCu + uye Cu2 + pakupisa kwakanyanya, izvo zvino mhanyisa kuparara kwePVC.

3) Kuparadzwa kwesimbi ions pane polymers

Mamwe ma pigment ane mhedzisiro inoparadza pama polymers. Semuenzaniso, iyo manganese lake pigment CIPigmentRed48:4 haina kukodzera kuumbwa kwePP zvigadzirwa zvepurasitiki. Chikonzero ndechekuti inoshanduka mutengo wesimbi manganese ions inokonzeresa hydroperoxide kuburikidza nekufambiswa kwema electrons mu thermal oxidation kana photooxidation yePP. Kuparara kwePP kunotungamirira kukukura kukuru kwePP; iyo ester bond mu polycarbonate iri nyore kuve hydrolyzed uye yakaora kana ichipisa, uye kana paine simbi ions mu pigment, zviri nyore kukurudzira kuparara; simbi ions inosimudzirawo iyo thermo-oxygen decomposition yePVC uye zvimwe zvinhu mbishi, uye kukonzera shanduko yeruvara.

Kupfupisa, kana uchigadzira zvigadzirwa zvepurasitiki, ndiyo nzira inogoneka uye inoshanda yekudzivisa kushandiswa kwemavara ane mavara anopindirana nezvinhu zvakasvibirira.

3. Kuita pakati pemavara uye zvinowedzera

1) Kuita pakati pesarufa-ine pigment uye zvinowedzera

Sulfur-containing pigments, yakadai secadmium yellow (solid solution yeCdS neCdSe), haikodzeri PVC nekuda kwekusagadzikana kweasidhi, uye haifaniri kushandiswa neine lead-ine additives.

2) Kuita kwemutobvu-ine makomisheni ane sulfur-ine stabilizers

Iyo inotungamira zvirimo mu chrome yero pigment kana molybdenum tsvuku inopindirana ne antioxidants senge thiodistearate DSTDP.

3) Kuita pakati pe pigment uye antioxidant

Kune zvigadzirwa zvine maoxidants, akadai sePP, mamwe pigment achaitawo ne antioxidants, nokudaro achideredza basa rema antioxidants uye kuita kuti kupisa kweokisijeni kugadzikane kwezvinhu zvakasvibirira kuwedzere. Semuenzaniso, phenolic antioxidants inotorwa nyore nyore nekabhoni dema kana kuita navo kuti varasikirwe nebasa ravo; phenolic antioxidants uye titanium ions muzvigadzirwa zvepurasitiki zvichena kana zvitsvuku zvinoumba phenolic inonhuwira hydrocarbon complexes kukonzera kutsvuka kwezvigadzirwa. Sarudza akakodzera antioxidant kana kuwedzera anobatsira anowedzera, akadai anti-asidhi zinc munyu (zinc stearate) kana P2 mhando phosphite kudzivirira discoloration chena pigment (TiO2).

4) Kuita pakati pe pigment uye light stabilizer

Mhedzisiro yepigment uye light stabilizers, kunze kwekuita kwesarufa-ine pigment uye nickel-ine light stabilizers sezvatsanangurwa pamusoro, kazhinji inoderedza kushanda kwemwenje stabilizers, kunyanya mhedzisiro yekuvharira amine light stabilizers uye azo yero uye tsvuku pigments. Mhedzisiro yekuderera kwakadzikama inonyanya kuoneka, uye haina kugadzikana senge isina ruvara. Hapana tsananguro chaiyo yechiitiko ichi.

4. The Reaction Between Additives

Kana akawanda ekuwedzera akashandiswa zvisina kunaka, maitiro asingatarisirwe anogona kuitika uye chigadzirwa chinochinja ruvara. Semuyenzaniso, inodzoreredza murazvo Sb2O3 inopindirana nesarufa-ine anti-oxidant kugadzira Sb2S3: Sb2O3+–S–→Sb2S3+–O–

Naizvozvo, kutarisirwa kunofanirwa kutorwa mukusarudzwa kwezvinowedzera kana uchifunga nezvekugadzira magadzirirwo.

5. Auxiliary Auto-oxidation Inokonzera

Iyo otomatiki oxidation ye phenolic stabilizers chinhu chakakosha kukurudzira kubuda kwemavara machena kana akajeka-mavara zvigadzirwa. Iyi discoloration inowanzonzi "Pinking" kune dzimwe nyika.

Iyo inosanganiswa ne oxidation zvigadzirwa senge BHT antioxidants (2-6-di-tert-butyl-4-methylphenol), uye yakaumbwa se3,3',5,5'-stilbene quinone light red reaction product, Uku kushanduka kunoitika. chete pamberi pe okisijeni nemvura uye pasina chiedza. Kana yakafumurwa kune ultraviolet mwenje, mwenje tsvuku stilbene quinone inokurumidza kuora kuita yero-single-ring chigadzirwa.

6. Tautomerization yeColour Pigments pasi peChiito cheChiedza uye Kupisa

Mamwe mavara ane mavara anoenda tautomerization yekumisikidzwa kwema molecular pasi pechiito chechiedza uye kupisa, sekushandiswa kweCIPig.R2 (BBC) pigments kuchinja kubva kune azo type kuenda kune quinone type, inoshandura iyo yekutanga conjugation mhedzisiro uye kukonzera kuumbwa kwe conjugated bond. . kuderera, zvichikonzera shanduko yeruvara kubva parima rebhuruu-kupenya dzvuku kuenda kuchiedza orenji-tsvuku.

Panguva imwecheteyo, pasi pe catalysis yechiedza, inoparara nemvura, ichishandura co-crystal mvura uye inokonzera kupera.

7. Zvinokonzerwa Nezvinosvibisa Mhepo

Kana zvigadzirwa zvepurasitiki zvakachengetwa kana kushandiswa, zvimwe zvinogadzirisa zvinhu, zvingave zvinyoro, zvinowedzera, kana mavara emavara, anozosangana nehunyoro mumhepo kana kusvibisa kwemakemikari senge acids uye alkalis pasi pekuita kwechiedza nekupisa. Yakasiyana-siyana yakaoma kemikari maitiro inokonzerwa, izvo zvinozotungamira mukupera kana kushanduka nekufamba kwenguva.

Mamiriro ezvinhu aya anogona kudziviswa kana kuderedzwa nekuwedzera akakodzera ekupisa okisijeni stabilizers, light stabilizers, kana kusarudza yakakwirira-mhando yemamiriro ekunze ekuwedzera uye pigment.